Distinguish ventilation from external respiration.

Distinguish ventilation from external respiration.

• A. Ventilation is the exchange of gases between alveolar air and blood.
• B. Ventilation is the air movement into and out of the lungs; external respiration is the exchange of gases between alveolar air and blood.
• C. Ventilation is diffusion of O2 into tissues.
• D. Ventilation and external respiration are identical processes.

Answer: (B)